1. Field of the Invention
The present invention relates to an RFID (Radio Frequency IDentification) tag through which information is exchanged with external equipment in a non-contact manner. The “RFID tag” used in the specification of the present application is called “radio IC tag” by persons skilled in the technical field of the application in some cases.
2. Description of the Related Art
Conventionally, there are various known RFID (Radio Frequency IDentification) tags through which information is exchanged with external equipment in a non-contact manner utilizing radio wave. As one kind of such RFID tags, there is proposed a tag having an IC chip and a radio wave communication conductive pattern (antenna pattern) provided on a base sheet. The RFID tag of such a type can be utilized in such a manner that the RFID tag is pasted on electronic equipment, information concerning the electronic equipment is exchanged with external equipment, thereby identifying individual electronic equipment. Recently, like an RFID tag (see Japanese Patent Application Publication No. 10-193848 for example) in which an IC chip having a communication function and an IC chip having an analyzing function for analyzing information transmitted through radio wave are pasted through an electric conductor (anisotropic electric conductor) having conductivity only in one direction, there is proposed an RFID tag having laminated IC chips.
Incidentally, there are the demands for reduction in size, weight and cost of the RFID tag. It is preferable that a structure of the RFID tag is simple and the tag can be manufactured with a simple technique. According to the RFID tag of the Japanese Patent Application Publication No. 10-193848, it is necessary to interpose an anisotropic electric conductor between the two IC chips when the two IC chips are laminated on each other. Thus, the RFID tag has a drawback that the thickness of the entire RFID tag is increased. According to the RFID tag of the Japanese Patent Application Publication No. 10-193848, as it is necessary to electrically connect the two IC chips to each other through a special member, i.e., the anisotropic electric conductor, it is not so easy to realize a desired conductive state.
Thus, according to the RFID tag of the Japanese Patent Application Publication No. 10-193848, it is difficult to reduce the size, weight and cost of the tag.